1. Field of the Invention
The present invention relates to an optical storage device, a recording method of an optical storage medium, and a program for performing the recording and reproduction of information by using a laser beam, and in particular, it relates to an optical storage device, a recording method of an optical storage medium, and a program which optimizes a retry in case an error occurs in recording and reproduction operations of the optical storage medium including a MSR medium which records and reproduces a data in density smaller than a beam diameter.
2. Description of the Related Arts
Heretofore, in general, an optical storage reproduction device such as a MO drive and the like has been provided with a write retry function at the recording time to the medium, and a read retry and a verify retry function at the reproduction time from the medium. The recording to the medium has been made in order of an erase, a write, and a write verify. There exist a great many number of parameters for changing a setting value in such a retry. In the parameters of a read retry and a verify retry, there are a cut off frequency of a regenerative magnetic field, a read power, and a low pass filter, a slice level of a boost and a slice circuit, a window value (window delay time) of a data discriminator, and a focus offset. Further, in the parameter of the write retry, there are an erase power, a write power, an erase magnetic field, and a write magnetic field. By using such retry functions, a write error and a read error are prevented.
However, in such a conventional optical storage reproduction device, even when the retry function is used, the write error and the read error are not completely prevented. As a main cause thereof, a recording to the medium by a deviated write power is conceivable. Even when there does not occur the write error or the read error due to this deviation of the write power, there still occurs the read error. Hence, it is necessary to take measures for preventing the recording to the medium by the deviated write power. As a cause of the deviation of the write power, there are cited various factors such as a variation of device, a characteristic of medium, a deviation of the focal point, and the like. Particularly in recent years, a focal length of object lens has come to be short due to miniaturization of the optical system, and there is a possibility of occurrence of the write error due to a deviation of focal point.
According to the present invention, there are provide an optical storage device, a recording method of an optical storage medium and a program, which optimizes the retry in case an error occurs by the recording operation of an optical recording medium.